"A test to determine that the brass jags would cause "blue patch after blue patch" would be to expose the brass jag to a wet patch.... ", not having any Bore Tech stuff I did just that with blob of Gun Slick Foam and Hoppes's 9 Black. The results are shown: As shown the 1st shot was at 14:17, the 2nd at 14:19, the 3rd at 14:22. As seen there is blue stuff on the patches. At least 3 minutes elapsed between the application and removal. Would the patch be exposed to the solvent the entire 3 minutes inside the bore? Probably yes. Would the reaction between the solvent and brass jag producing the blue stuff detract from the efficacy of the solvent on the copper fouling? No. Would the blue stuff on the patch prevent an accurate evaluation of how well the solvent was working on the copper fouling? yes. Was I wrong in stating that "trails of copper fouling caused the blue patches" ? not entirely provided copper fouling was present. "We all have our ways to clean rifles" Gun Slick Foam is my choice because it is a foam and not subject to as much evaporation as a water based liquid. Upon pushing the over night foam out of my rifle barrel the resulting mess is dark blue-black glop. The black stuff is probably powder and primer residue with some copper fouling preventer like tin. I leave the Gun Slick foam inside the bore for about 8-10 hours. Then scrub out the bore real good with a nylon brush & syn 0-20W. Drench some of the Bore Tech stuff on patches & jags and feed back some photos. I hope to have a bore scope soon to play around with the copper fouling and black stuff.